Improvement in plumb-levels



ZIMMERMAN 6L BAKR.

y .Pluim Level.'

Patented om. 6, 1867.

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- @eine tutes gamut @ffice JOHN T. ZIMMERMN ANI) HENRY lBAISER, OF LANCASTER, PENN- SYLVA N IA.

i Letters Patent No. 69,602, dated October S, 1867.

IMPROVEMENT IN PLUME-LEVELS.

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T0 ALL WI-IO-M IT MAY CONOERN:

Bc it known that we, JOHN T. ZIMMERMAN and HENRY BAKER, of Lancaster, inthe county of Lancaster,

and State of Pennsylvania, have invented a new and useful Improvement on Plumb-Levels; and we do hereby declare that the following is a full, clear, and exact description of thc construction and operation ot' thc` same, referencebeing had to theaccompanying drawings, making a part of this specification, in which- Figure 1 is a perspective view o f theinstrument` Figure 2 the disk, with thejn'dex andadjustment-plate, (a front View.)

Figure 3 a vertical side View or elevation of the instrument with a straight-edge indicated in the clampscrews.

The objcctotv this invention is to'improve that class of levels in which the position of the index-hand is governed by the action of a weighted end swinging on an axle poised on conic or needlepoints in countersunk cavities.

The improvement consists in the addition of a slotted piece suspended on the axle of the index, and connected with it by a screw for adjusting the balance of the weighted end, so as to centralize the index-points to coineide with the true plumb or level of the base orclamped straight-edge connected with the instrument, and to facilitate thettingup and regulating the instrument when impaired by use or otherwise.

To enable others skilled in the art to make and use our invention, we will proceed to describe its construction and operation.

Fig. 1 shows a circular disk, A, aixed to or cast with the rear bracketA AB', and is graduated to indicate inches and their fractions, or degrees, between the four cardinal points, the horizontal and perpendicular lines at right angles to each other. In connection with the rear support or bracket B", with its additional base D, there is an anterior bracket, B, meeting in an ornamental head in advance of the centre of the disk; the said connection being formed by a cross-piece, c, at each end, which has a head, o, for a screw-thread, into which the screw E, with its milled head, fits, for binding a strip of wood, N, of any desired length or thickness between it and the extended rear base D, tig/i 3. The index F is shown .by g. 2 on the disk, with its four points f, and weightedquadrant-like base, showing a central hole in it, with a screw-thread cut in it for the reception of a binding-screw, H. The slotted regulating-plate G being suspended on the axis of and in front of the index F, is held or adjusted by means 4of the said binding-screw H entering the slot z' on the curved base t of the same. The index F has an axis, M, with conic or needle points, held in arcountersink in the centre of the disk on the rear of the index, and a countersink in a headed bolt, L, in front. This bolt enters horizontally through the crnamented central union of the brackets. B, and held in place bv a vertical set-screw, K, entering from the top, as shown by'g. 3.'

We are aware that a patent, 49,802, for a pendulum-level, claiming an index-hand extending from the extreme hand of the pendulum, and bent around the edge of th-e dial, in combination with a central stud, was granted in September, 1865, and, subsequently, patent 51,564, in which a combined gravitation, level and inclinometer is claimed, when constructed with a glass face, having a central couutersink for the reception of the pivot orlaxis of the index, and held in the rear by a screw, which we admit to be analogous to our mode, differing, however, in the important point that one end is supported in a glass cover, so dilicult to centralize i' and easily broken, that we emphatically disclaim' that method et' suspending the index-hand, as also the circuluropeningin the top of the easing. The difference of our combination and arrangement consists in having 1 1. four-pointed index to enable us to usc the instrument over head, in .a reversed position, also to facilitate the fitting up and eentralizing the points by means of the adjustingplatc, and also the clamp base for applying a straight-edge. of any desired length, constituting an instrument differing substantially from all others of its class.

What we claim as our invention, and desire to secure by Letters Patent, is- 1. The regulating-plate G, with its base L and slot i, and binding-screw H, in combination with the index F, provided with four pointsj'ffj, constructed and operating inr the manner specified.

2'. We.also claim the arrangement of the united supports B Il', by the cross-plates C, in combination with the clamping-screws E, when constructed in the manner and for the purpose set forth.

JOHN T. ZIMMERMAN. I' ,IIENRY BAKER.

Witnesses:

Jolien-M. Anwen, JACOB S'rAUFrnn. 

